The present invention relates to methods of promoting the growth of beneficial bacteria in the gut of a human in need thereof, which involves administering to a human a composition containing an effective amount of Ara-(1-5)-(Ara)n-(1-5)-Ara (n=0-18, preferably 0-13) as a prebiotic.
The human gastrointestinal tract is a highly complex microbial ecosystem which has been shown to be remarkably stable (Zoetendal, E. G., et al., Applied and Environmental Microbiology, 64: 3854-3859 (1998)). Many different approaches have been used to modulate the gut flora in a way that is beneficial to host health (Bielecka, M., et al., Food Research International, 35: 125-131 (2002); Steer, T., et al., Nutrition Research Reviews, 13: 229-254 (2000)). These include the addition of living microorganisms to food (probiotics), the addition of food ingredients or dietary fibre to selectively stimulate beneficial bacteria within the host (prebiotics), and a combination of both probiotics and prebiotics (synbiotics). The usual targeted outcome is an increase in the numbers of lactobacilli and bifidobacteria. As an alternative to the addition of live bacteria to the diet, prebiotics have been defined as non-digestible food ingredients that selectively stimulate the growth and/or activity of one or a limited number of bacteria in the colon, and thus improves host health (Gibson, G. R., and M. B. Roberfroid, Journal of Nutrition, 125: 1404-1412 (1995)). All current prebiotics are resistant to the digestive process as they have to reach the colon intact in order to be able to be fermented by the beneficial bacteria lactobacilli and bifidobacteria. The bifidogenic nature of a number of prebiotics has been confirmed in vivo in human feeding studies (Saavedra, J. M., and A. Tschernia, British Journal of Nutrition, 87: s241-s246 (2002); Tuohy, K. M., et al., British Journal of Nutrition, 86: 341-348 (2001); Tuohy, K. M., et al., Microbial Ecology in Health and Disease, 14: 165-173 (2002). These include inulin, fructo-oligosaccharides (FOS), galacto-oligosaccharides (GOS), and lactulose.
We have found that orange pectic oligosaccharides (POS) are rich in arabino-oligosacchrides and these oligosaccharides may be used as a prebiotic.